System for grinding and polishing glass sheets



Aug. 18, 1931. J. L. DRAKE SYSTEM FOR GRINDING AND POLISHING GLASS SHEETS Filed June 29, 1929 7 Sheets-Sheet l c/ohn L. Drake Aug. 18, 1931.- J. 1.. DRAKE SYSTEM FOR GRINDING AND POLISHING GLASS SHEETS Filed June 29. 1929 '7 Sheets-Sheet 2 T'l'llil- E1- gjwuentoz 00hr; L. Drake Aug. 18, 1931. J. L. DRAKE 1,819,017

SYSTEM FOR GRINDING AND POLISHING GLASS SHEETS Filed June 29, 1929 7 Sheets-Sheet 3 Aug. 18, 1931.v J. DRAKE SYSTEM FOR GRINDING AND POLISHING GLASS SHEETS Filed June 29, 1929 7 Sheets-Sheet 4 gwuentoz o/ohn L. Drake.

18, 1931- J. L. DRAKE 1,819,017

SYSTEM FOR GRINDING AND POLISHING GLASS, SHEETS Filed June 29, 1929 7 Sheets-Sheet 5 E 1 gnuwfloz dohn L. Drake.

Aug. 18, 1931. J. DRAKE SYSTEM FOR GRINDING AND POLI SHING GLASS SHEETS Filed June 29. 1929 '7 Shepats-Sheet 6 E :1. :21. 15.. gwue'ntoz dohn L. Drake.

dam Mq Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE JOHN L. DRAKE, OF TOLEDO, OHIO, ASSIGNOR TO LIBBEY-OWENS-FORD GLASS COM- PANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO Application filed June 29,

The present invention relates broadly to the surfacing of glass sheets or other flat sheets or plates of material and more particularly to such a system wherein the grinding and polishing of the sheets or plates is performed in a straight-away operation.

The system herein provided is primarily designed for the continuous surfacing of sheet glass and consists of two substantially to parallel tracks, one constituting the Working track and the other the return track. Adapted to be mounted above the working track are a series of grinding and polishing units and suitable cars or tables are movable along this track to carry the glass sheets secured to the tops thereof beneath and in engagement with the grinding and polishing units. After the grinding and polishing operations have been completed, the glass sheets are removed from the cars or tables and the said cars or tables transferred to the return track along which they are moved to the starting end of the working track. The transfer means herein provided for transferring the cars or tables rom one track to the other consists preferably of a rotatable transfer or turn table provided at each end of the parallel tracks, the turn table at one end of the tracks being operated in a manner to receive the cars-"or tables from the working track and discharge them onto the return track, while the turn table at the opposite end is provided to receive the cars or tables from the return track and discharge them onto the working track.

The primary object of the present invention consists in the provision of mechanical means operable in such a manner that the handling andtransfer of the cars or tables from one track to the other track may be accomplished automatically and without any manual aid or assistance.

Another object of the invention resides in the provision of safety means for various parts of the system which will render the operation of such parts dependent upon the proper operation and positioning of other parts of the system whereby to provide apparatus. which will operate to effect the handling and transfer of the cars or tables 1n 1929. Serial No. 374,881.

an effective and efficient manner, with safety and ease of operation.

With respect to the above object, it is an aim of this invention to provide safety means for preventing the rotation of the turn table until the means employed for dischargin the cars 'or tables from said turn table has een moved to a proper position and stopped; to provide safety means for preventing the operation of the means used for discharging the'cars or tables from the turn table until said turn table has been properly positioned with respect to the working and return tracks; to provide means for preventing the rotation of the turn table during the removal of the cars or tables therefrom; and further, to provide means for indicating to an operator when the cars or tables moving along the return track are not in properly spaced relation with respect to one another.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings wherein like numerals are employed to designate like parts throughout the same,

Fig. 1 is a diagrammatic top plan view of one end of the grinding and polishing system provided by the present invention,

Fig. 2 is a similar view of the opposite end thereof,

Fig. 3 is a similar view of that portion of the system intermediate the two ends thereof,

Fig. 4 is a side elevation of one of the overhead pushers,

Fig. 5 is a transverse section therethrough showing the manner in which the pusher elements are supported,

Fig. 6 is a sectiontaken substantially on line 6-6 of Fig. 5, I

Fig. 7 is an end view of the overhead pusher, partially in section,

Fig. 8 is a section taken substantially on line 88 of Fig. 2,

Fig. 9 is a detail view of the turn table stopping means,

Fig. 10 is a detail view of the overhead safety switch,

Fig. 11 is an end View of one of the tables showing the arrangement of the table locating switch,

Fig. 12 is a detail section through the operating car,

Fig. 13 is a top plan View of one of the table locating switches or table clearance switches,

Fig. 14 is a section taken substantially on line 1414 of Fig. 1,

Fig. 15 is an end elevation of one of the overhead pushers at the forward end of the working line, and

Figs. 16, 17 and 18 are wiring diagrams showing the electrical wiring for the various parts of the system.

Referring to the drawings, there is employed in the present system the two main longitudinally extending parallel tracks 20 and 21, the track 20 constituting the working track and track 21 the return track. Mounted above the working track 20 are a plurality of grinding runners 22 and a plurality of polishing runners 23, and while only one grinding and polishing runner has been shown by way of illustration, any desired number may be employed, with the polishers preferably spaced a considerable distance from the grinders. Adapted to be carried along the tracks 20 and 21 are a plurality of work cars .or tables 24, said cars or tables being mounted upon wheels 25 rolling along the tracks. The tables 24 are preferably coupled together during their travel along the working track 20 in order to present a substantially continuous unbroken surface upon which glass sheets 26 may be secured in any desired manner such as by embedding them within a layer of plaster of Paris or some other suitable plastic material 27.

The tables 24 'are adapted to be propelled along the working track 20 by any suitable type of driving means located preferably adjacent the rear end thereof and which driving means may take the form of a drive pinion 28 meshing with rack bars 29 secured to the undersides of the tables and driven from a motor 30 through suitable reduction gearing located in casing 31. The drive pinion 28 is adapted left along the working track 20 and after the tables have passed beneath the grinding and polishing runners, the glass sheets are removed therefrom, the tables uncoupled and transferred to the return track 21 which carries them to the starting end of working track 20.

, During the' movement of the tables 24 along the return track 21, they are maintained spaced from one another a predetermined distance and are adapted to be driven along said track by means of a longitudinally extending endless chain conveyor designated in its entirety by the numeral 32. The endless chain conveyor 32 is, as shown in Fig. 8,

to propel the line of tables to the adapted to be located beneath the tables as they move along the return track 21 and includes an upper horizontal flight 33 and the lower horizontal flight 34.- The chain conveyor 32 consists of a plurality of overlapping links pivotally associated in endless formation and connected together by cross shafts or pins 35. Mounted upon the opposite ends of the cross pins 35 are rollers 36, said rollers being guided along in the upper flight 33 of the endless chain 32 upon a trackway 3T supported upon horizontal transverse beams 38 while the rollers 36 in the lower flight 34 of the chain travel along upon a trackway 39 mounted upon a supporting structure 40. The endless chain 32 carries at a plurality of spaced points a number of pusher elements 41 which are adapted to engage plates 42 carried by and depending from the tables 24 at the forward ends thereof for pushing said tables to the right along the return track 21. The endless chain 32 is preferably trained at its opposite ends about suitable sprockets (not shown) but mounted upon shafts 43 and 44, one of which, preferably shaft 44, is positively driven from a motor 45 through suitable reduction gearing located in housing 46.

Provided at one end of the parallel tracks 20 and 21 is a rotatable transfer or turn table 47 and a similar transfer or turn table 48 is provided at the opposite end of said tracks. Each turn table preferably carries the four individual track sections 49, 50, 51 and 52, the track sections 49 and 51 being opposite and parallel with one another, while the track sections and 52 are also disof a motor 53 driving, through suitable re- 110 duction gearing, a drive pinion 54 which meshes with a ring gear 55 carried by said table.

Positioned outwardly of the turn table 47 and adjacent to one side thereof is an auxiliary track 56 disposed in alignment with the working track 20 and also with that individual track section on the turn table which happens to be in alignment with the working track. lhe auxiliary track 56 is provided primarily to carry an operating car or dinkey 57 which is mounted upon wheels (not shown) but which are adapted to roll along the track 56. The operating car also carries suitable coupling means 58 adapted to engage the adjacent end of the work tables on the working track so as to pull said tables onto the turn table. The particular construction and operation of the car or dinkey 57 is more fully described and claimed in my 'copending application filed June 29, 1929, Serial No. 374,882.

An overhead pusher, designated in its entirety by the numeral 59, is provided for pushing the work tables from the turn table 47 onto the return track 21, while located at the opposite end of the system is an overhead pusher 60 for pushing the tables 24 from the turn table 48 onto working track 20, while a third overhead pusher 61 is provided for simultaneously pushing a work table from the return track 21 onto turn table 48.

The particular construction of the overhead pusher 59 is disclosed in Figs. 4 to 7 inclusive and upon reference thereto, it will be noted that the same comprises an endless chain composed of a series of overlapping links 62 pivotally associated with one another and mounted upon cross shafts or pins 63, said chain being trained about horizontally spaced sprockets 64 and 65 with the teeth thereof received between the spaced links.

The lower flight of the chain travels between the spaced horizontal supporting members 66 and 67 carried by the angle beams 68 and 69 to prevent the chain from sagging, while the upper flight travels between corresponding supporting members 66 and 67 carried by similar angle beams. The sprocket 65 is mounted upon a shaft 70 journaled at its opposite ends in bearings formed on bracket plates 71 secured to the horizontal channel beams 68 and 69. On the other hand, the sprocket 64 is preferably adjustable hori zontally toward and away from sprocket 65 v and to this end the shaft 72 carrying sprocket 64 is supported in slidable bearing blocks 73 mounted for horizontal sliding movement upon the guide 74 carried by the supporting member 75, secured to channel beams 68 and 69. The slidable bearing blocks 73 may be moved inwardly or outwardly upon the guides 74 by the provision of adjusting screws 76 operable by hand wheels 77. 7 Carried by two of the links 62 of the overhead pusher are brackets 78 and 79, each bracket being formed at its outer end with a tubular portion or cylinder 80 within which is slidably mounted a pusher element 81, the inner end of said element being reduced in diameter as at 82 and extending through the end wall of the cylinder 80. Threaded upon the re duced end of the pusher elementoutwardly of the cylinder, is a nut 83, while encircling the reduced portion of said pusher element within cylinder 80 is a compression spring 84 tending to yieldably urge the pusher element outwardly. The. overhead pus'her59 is adapted to be driven from a motor 85 connected with the shaft through suitable reduction gearing located in casing 86. Thus, upon operation of motor 85 to move the overhead pusher in a counter-clockwise direction, one of the pusher elements 81 will engage the work table upon that track section of the turntable in line with the return track and move said table from the turn table onto said track, the pusher element yieldably engaging the rear end of the table as shown in Fig. 4.

1 The overhead pushers 60 and 61 at the opposite end of the system are of substantially the same construction as overhead pusher 59 with the main exception that they are adapted to be driven in unison from a single motor 87, said motor being operatively connected, through suitable reduction gearing located in casing 88, with a shaft 89 associated with one of the sprockets of overhead pusher 60, and through shafts 90 and 91 with one of the sprockets of the overhead pusher 61, shaft 90 being connected with shaft 89 through the bevel gears 92 and 93, while the shaft 90 is connected with shaft 91 through the bevel gears 94 and 95. Thus, upon operation of motor 87, the overhead pushers 60 and 61 will be simultaneously driven to move one of the work tables 24 from the return track 21 onto turn table 48 and another work table from turn table 48 onto working track 20.

The handling of the work cars or tables 24 in the present system, may be stated briefly as follows:

A work table 24 is initially run from turn table 48 by means of the overhead pusher 60 onto the forward endof working track 20 where said table is coupled with the preceding tables upon said track to form a continuous train. Also, at the forward end of the working track, the glass sheets 26 are adapted to be secured to the tops of the tables. The tables are then driven. along the working track in a continuous'train by means of the drive pinion 28 engaging racks 29 upon the un'delsides of the tables so that said tables will move to the left along the working track to carry the glass sheets first beneath the grinding runners 22 and then beneaththe polishing runners 23. When the tables 24 reach the opposite end of the working track, the operating car or dinkey 57 is caused to move forwardly across the turn table 47 and' its direction of travel is reversed so a's-to' pull said table onto the track section of the turn table which is in alignment with the working track, and as illustrated, track section 49. When the table is in proper position upon the turn table, the operating car 57 releases the same and passes rearwardly onto the auxiliary track 56. V The turn table is then intermittently rotated until the track section upon which the work table is stationed is brought into alignment with the return track 21, whereupon the overhead pusher 59 is operated to move the table 24 from the turn table onto the return track along which said table is driven to the right by the endless chain conveyor 32 above described, to the opposite end of said return track, where it is engaged by the overhead pusher 61 and moved onto turn table 18. The turn table 18 is then intermittently rotated to bring the track section of the turn table upon which the work table is stationed intoalignment with the working track 20, whereupon said table is again pushed onto said track by the overhead pusher 60 to complete the cycle of travel on the work table.

As brought out above, it is an aim of this invention to efiect the above handling of the cars or tables automatically and without any manual aid or assistance. To this end, there are positioned between the railso'f the work ing track 20, adjacent the turn table 17, the three switches 96, 97 and 98, said switches being positioned in longitudinal alignment with one another with the switches 96 and 97 relatively close together. Also positioned between the rails of the auxiliary track 56 are two similar switches 99 and 100, said switches being in longitudinal alignment with the previously mentioned switches 96, 9? and 98. There is further positioned outwardly above but adjacent to the working track 20, a switch 101. The several switches referred to above are preferably of the same construction and each is adapted to be controlled, as shown in Figs. 12 and 14:, by the' provision of a star-wheel or the like 102 having a plurality of radiating actuating fingers 103. The switches 96, 98, 100 and 101 are connected in series with the motor 104 provided to operate the dinkey 57, while the switch 97 is connected in series with motor 85 for the overhead pusher 59, and the switch 99 is connected in series with the motor 53 for turn table 4-7.

In operation and upon movement of the work tables 24: to the left along working track 20, the depending plate 42 (Fig. 14) carried at the forward end of the work table, will engage the star-wheel 102 of switch 96 and rotate said wheel in a manner to close said switch. This will complete an electrical circuit through the dinkey motor 104 to start the dinkey forwardly across the turn table 17, and such forward movement of the dinkey will continue until the projection 10!) (Fig. 1), carried upon the outer side of said dinkey, engages the star-wheel 102 of switch 101 and actuates said switch to break the cir-' cuit through the dinkey motor 104 and bring the dinkey to a stop in its position indicated by the broken lines to the right in Fig. 1.

During the forward movement of the dinkey, the work tables 24 are continuously moving to the left along the working track 20, and next actuates switch 97 which will complete the circuit through the motor 85 and start the operation of the overhead pusher 59 to remove the work table from the track section 51 of the turn table onto the return track 21. Upon continued movement of the work tables along working track 20, the end table will next actuate switch 98 which will again close or complete the circuit through the dinkey motor 10 1 to start the dinkey rearwardly. Just prior to the operation of switch 98, however, the dinkey is adapted to be automatically coupled to the end table 24 by the coupling means 58 so that upon rearward movement oi the dinkey, it will pull the end work table 2A1 therewith onto the turn table. W" hen the work table 24': reaches a predetermined position upon the turn table, the dinkey is adapted to be automatically uncoupled therefrom by any suitable means to permit said table to rest upon the turn table while the rearward movement of the dinkey is continued.

As the dinkey 57 passes rearwardly ifrom the turn table 4:7, the depending plate 108 (Fig. 12) pivoted to the rear end of dinkey 57 as at 107, will engage the star-wheel 102 of switch 99'and rotate the same so as to close said switch, which will complete the circuit through the turn table motor 53, and eilect the rotation of said turn table a quarter of a revolution. Upon continued rearward movement of the dinkey, the pivoted plate 105 will actuate switch 100 to again break the circuit through the dinkey motor 104 and bring said dinkey to a stop. Upon rotation of the turn table a quarter of a revolution, the car resting upon track section 52 will be brought into a position to be discharged upon the return track 21, while the empty track section 50 will be brought into operative relation with respect to the working track 20 to receive another car therefrom, whereu on the above cycle of operations is repeate'.

According to the present invention, means is provided for automatically bringing the overhead pusher 59 to a stop after the work table has been removed from the turn table onto the return track and when said overhead pusher is in a predetermined position and likewise to provide a safety means or switch for preventing the rotation of the turn table until said overhead pusher has been operated to remove the table from said turn table and stopped in its proper position for the removal of the next table. To this end, there is carried by the horizontal supporting channel beam 69 for the overhead pusher, a vertical bracket arm 108 carrrying the switch 109 having the operating starwheel 110, said switch being connected in series with the overhead motor 85. Also carried by each bracket member 7 9 on the overhead pusher is a transverse plate 111. In practice, when the pusher element 81 disengages the table 24 and passes upwardly to its broken line position indicated at the rlght in Fig. 4, the plate 111 carried thereby will engage and rotate the operating wheel of switch 109 and thus open said switch and lit] break the circuit through the overhead motor 85 to bring the overhead pusher to a stop.

p a laterally projecting Also carried by the horizontal-channel beam 69 is a snap switch 112 having the operating finger 113, carrying roller 114. The switch 112 is connected in series with the motor 53 for the turn table 47 and is normally urged into an open position so that the turn table will not be permitted to rotate until this switch is closed and the said switch will not be closed until it is engaged by the pusher element and the overhead pusher thus brought to a stop at the proper position. Due to the provision of the safety switch 112 for the turn table 47, unless the overhead pusher 59 is in proper position to close the switch 112, the closing of the switch 99 by the dinkey 57 will have no effect upon the rotation of the turn table.

Means is also provided whereby the overhead pusher 59 cannot be operated to move a work table 24 from the turn table 47 unless the individual track section on the turn table is in proper alignment with the rails of the return track so that there will be no danger of the overhead pusher operating to push acar from the turn table until said turn table is properly located. To accomplish this, there is provided, as illustrated in Fig. 10, a fixed switch 115 which is also connected in series with the overhead motor 85, said switch being controlled by pivoted arm 116 having lug or pin 117. Carried by the turn table 47 is a vertically disposed plate 118 having a bevellededge 119. The switch 115 is normally opened, but when the turn table is rotated and brought to a stop in the proper position with respect to the working and return tracks 20 and 21, the pin 117 carried by plate 116 will ride upon the bevelled edge 1190f plate 118 so as to close the switch 115, and upon closing of said switch, the overhead pusher can be operated upon closing of the overhead start switch 97 The switch 115 can also be connected in series -with the dinkey motor 104, if desired, to prevent operation of the dinkey unless the turn table is properly positioned.

According to the invention, it is further proposed, in order to avoid excessive jar and shock to the various parts of the apparatus, to provide for the gradual stopping of the turn table instead of a sudden stopping thereof. To provide for this, there is utilized, as disclosed in Figs. 9 and 10, a switch 120 controlled by the star-wheel 121;-Carried by the turn table 47 are a pair of spaced vertical plates 122 and 123. The switch 120 is constructed in a particular manner to be more fully hereinafter described, so that upon rotation of the turn table, the plate 122 first engaging star-wheel 121 to actuate the switch 120, will cause a -slowing down of the turn table motor 53 and turn table 47, after which plate 123 engaging star-wheel 121to again operate switch 120 will act to completely shut oil the motor 53 and thereby bring the turn table to a stop.

After the work'tables 24 are moved from the turn table 47 to return track 21, they are carried or pushed to the right by means of the endless carrier 32 above described. Positioned between the rails of the return track, adjacent the turn table 48, is. a. switch 124 shown in Figs. 2 and 8, and controlled by the starqvheel 125. Upon movement of the table to the right along the return track, the depending plate 126 carried at the rear end of the table is adapted to actuate the starwheel 125 of switch 124 and close the same. This switch is connected in series with the motor 87, so that upon closing of said switch, the motor will be placed in operation to simultaneously operate the two overhead pushers 60 and 61, the pusher 61 serving to push the table which has just actuated swltch 124 onto turn table 48, while overhead pusher 60 moves one of the tables 24 from the turn table onto working track 20.

As described above in connection with overhead pusher 59, the overhead pushers 60 and 61 are also adapted to beautomatically stopped when they are in proper position,

and upon stopping of the overhead pushers, the turn table 48 is adapted to be rotated a quarter of a revolution. The arrangement for accomplishing the above is best shown in Fig. 15 wherein two vertical supporting brackets 127 and 128 are carried by the channel members 68 and 69 of overhead pusher 60 at the forward end thereof. Supported by the bracket arms 127 and 128 are the switches 129 and 130 controlled by the star-wheels 131 and 132 respectively. Thus, after the overhead pusher 60 has been operated to remove a work car 24 from the turn table 48 onto working track 20, the pusher element will pass upwardly and the plate 111 carried thereby will engage the star-wheels 131 and 132 to rotate thesame in a manner to open switch 129 and close switch 130. The switch 129 is connected in series with the overhead motor 87 while the switch 130 is connected in series with the turn table motor 53. Thus, the opening of switch 129 will bring the overhead'pusher to a stop, while the'closing of switch 130 will actuate the turn table. A safety switch 133, similar to switch 112 above described, may be provided and connected in series with the turn table motor 53 of turn table 48 to prevent rotation of said turn table until the overhead pushers are brought to a stop at the proper positions. A suitable overhead safety switch, similar to switch 115,

in series with motor 53 for the turn table and normally maintained in a closed position. However, duringthe movement of the table 24 from the turn table 47 onto the return track, the table engaging the switches 134 and 135 will act to open the same and thus break the circuit through motor 53 so that said motor cannot operate until the table has passed completely beyond and out of contact with both switches 134 and 135. The same means may be provided at the oppo site end of the system for preventing rotation of the turn table 48 during the time the cars are passing therefrom onto the working track 20.

The operation of each of the table clearance switches 134 and 135 may be controlled by the means illustrated in Fig. 13, wherein the numeral 137 designates the switch arm to the outer end of which is pivoted as at 138, a cylinder 139. Mounted within cylinder 139 is a plunger 140 and pivoted to the outer end of said plunger as at 141 is a rocker lever 142, fulcrumed intermediate its ends as at 143, and carr ing at its outer end a roller 144. Encircling t 139, is a compression spring which tends to draw the plunger 140 inwardly to rock the lever 142 outwardly about its pivot 143 and into the position indicated by the full lines, so that the outer end of said lever is disposed in the path of the travel of the work tables 24. As above stated, the table clearance switches 134 and 135 are normally closed, but during the movement of the work table fromthe turn table, the table engaging the outer ends of levers 142 will rock the same to the position indicated by the broken lines in Fig. 13 which will eilect the opening of the switches so that the turn table cannot be rotated until the work car has passed out of engagement with the second switch 135.

There is also provided means for indicating to the operator when the work cars or tables moving along the return track are not. properly spaced from one another, and for this purpose, there is positioned between the rails of the return track, adjacent turn table 47, a table locating switch 146 shown in Figs. 1 and 11, said switch being carried by the upright 147 and controlled by an operating lever 148 havin a roller 149 at its upper end. Positione outwardly of but adjacent e plunger 140 within cylinder to the return track and forwardly of the switch 146, are the two switches 150 and 151 carried adjacent the opposite ends of a horizontal support 152. The switches 150 and 151 may be of the same construction as the table clearance switches 134 and 135 described hereinabove, and are connected in series with switch 146. Arranged in the same circuit with these three switches is an electric lamp or other indicating means 153. The switch 146 is normally open, while the switches 150 and 151 are normally closed. Thus, in operation, when a work car or table is moved from the turn table 47 onto the return track 21, the plate 126 carried by the table 24 will actuate switch 146 to close the same. When this occurs, however, the preceding table on the return track should be in a position opposite one of the table locating switches 150 or 151, and when in such position, the table will hold the switch open, so that the circuit through the indicating means will not be completed. On the other hand, should a table 24 not'be opposite one of the switches 150 or 151, upon closing of the switch 146, the circuit through the indicating means 153 will be'completed, and this will indicate to the operator that the work tables are not being engaged and carried along by the chain conveyor 32 at the proper intervals and at the desired speed with the result that the work tables on the return track will become either too close together or too far apart. When this occurs, the operator can either speed up or slow down the return chain conveyor 32 to cause the tables to be engaged by the chain conveyor at the roper intervals and be carried along at the desired speed so as to again bring the tables into properly spaced relation.

In Figs. 16, 17 and 18 is shown the electricalwiring arrangement for the various parts of the system. Referring first to Fig. 16, wherein is disclosed the wiring arrangement for the left hand end of the s stem as illustrated in Fig. 1, it will be note that the overhead start switch 97 is provided with three contacts 155, 156 and 157, from which lead the three wires 158, 159 and 160 respectively connected to the positive main 161. Leading from the other three contacts 162, 163 and 164 of switch 97 are the three wires 165, 166 and 167 respectively connected to the contacts 168, 169 and 170 of the overhead stop switch 109. Running from the contact 171 of said switch 109 is a wire 172 connected to the overhead motor 85, while leading from the contacts 173 and 174 of switch 109 are the two wires 175 and 176 connected to the wire 17 2 which leads to motor 85. Runnin from the motor 85 to the negative main 177 is a wire 178, within which is dis osed the safety switch 115. The switches 9 and-109 are provided with the rotatable switch arms 179 and 180 respectively adapted to connect thetwo oppositely disposed contacts of said switches.

The turn table start switch 99 is provided with the four contacts 181, 182, 183 and 184 and is operable by a three point rotatable switch arm 185. Leading from the contact 182 of switch 99 is a wire 186, and a wire 187 leads from contact 181 and is: connected with wire 186, which runs to the positive main 161. The turn table switch 120'illustrated in Fig. 9 comprises an operating shaft 188 upon the outer end of which the star wheel 121 is mounted, said shaft carrying a single switch arm 189 and a double switch arm 190, the said switch arms 189 and 190 operating as a unit upon rotation of shaft 188. The switch 120 also includes two separate sets of contacts with which the arms 189 and 190 are adapted to engage, the single switch arm 189 adapted, upon rotation thereof, to contact successively with the contacts 191, 192, 193 and 194, while the double switch arm 190 is adapted to engage contacts 195, 196, 197 and 198. Leading from the contact 183 of switch 99 is a wire 199 connected to both the contacts 191 and 192 of switch 120, while leading from contact 184 of switch 99 is wire 200 secured to contacts 193 and 194 of switch 120. Secured to and leading from the single operating arm 189 is a wire 201 connected with contacts 197 and 198 of switch 126, while leading from the contacts 195 and 196 are the wires 202 and e 203, respectively, connected to the turn table motor 53 which is of the variable speed type adapted to run alternately at a fast speed and then at a slow speed. From the variable speed motor 53 run the wires 204 and 205, the wire 205 being connected to wire 204 which leads to the negative main 177. Interposed within the line 204 are the work table clearance switches 134 and 135, and the turn table safety switch 112. The electrical wiring arran ement for the operating car or dinkey 57 as not been illustrated.

In operation, and when the operating arm 185 of switch 99, and operating arms 189 and 190 of switch 120 are in the positions' illustrated by the full lines in 16, the circuit through the turn table motor 53 is broken, and the said turn table consequently at a stand-still. On the other hand, when the arms 179 and 180 of switches 97 and 109 respectively are in their full line position, the overhead pusher 59 is operating to move a work table 24 from the turn table 47 onto return track 21. During this operation of the overhead pusher, the electric current will enter from the positive main, 161 and pass through wire 160, arm 179 of switch 97, to the wire 165, through switch arm 180 of switch 109, then through wire 172 to motor 85, and from motor 85 through wire 178 tothe negative main 177. Of course, the turn table 47 must be properly located to maintain the safety switch 115 closed, otherwise the circuit through the motor 85 could not be completed. The overhead pusher 59 will contlnue to rotate until the switch 109 is operated by the pusher unit and when this switch is opened,'the arm 180 thereof will be rotated to engage contacts 169 and-173 and thus break the circuit through the motor 85 to bring the overhead pusher to a stop.

During the operation of the overhead pusher 59, the operating car 57 is moving rearwardly across the turn table 47 to pull one of the tables 24 from the working track into a position upon the turn table: Upon continued. rearward movement of the operating car, the pivoted plate 106 carried thereby will actuate the turn table switch 99 in a manner to move the operating arm 185 thereof into engagement with the contacts 181 and 183, whereupon the electric current will enter from the positive main 61 and pass through wires 186 and 187, through the switch arm 185 to wire 199, thento the single operating arm 189 of switch 120, then through wire 201 to the switch arm 190, and then through Wire 202 to the variable speed motor 53, and from the motor through wire 204 to negative main 177 Upon closing of this circuit, the motor 53' will be driven ,at its faster speed to start the rotation of the turn table, and during the rotation of the turn table, the overhead pusher will be maintained stationary. The completion of this circuit is, of

into engagement with contact 192, and the double switch arm 190 into engagement with contacts 1 96 and 198. will then enter through wires 186 and 187, pass through switch 99, and wire 199 to contact 192 of switch 120, then through switch arm 189 and wire 201 to contact 198, through switch arm 190 and wire 203 to motor 53,

and from motor 53 through wires 205 and 20 1. Upon the completion of this circuit, the speed of the motor will be somewhat reduced, but not entirely stopped so as to slow down the speed of rotation of the turn table. However, when the plate 123 carried by the turn table then actuates switch 120, the single arm 189 thereof will be moved to engage contact .193, and the double arm 190 moved to enga e contacts 195 and 197. This will break the circuit through the turn table motor 53 as the current can no longer pass through the switch 120 whereby to bring said turn table to a stop.

The operating car 57 is then again moved forwardly across the turn table 47 to efi'ect the removal of "another table 24 from the The electric current V working track 20 onto said" turn table, and upon the removal of this table, the overhead start switch 97 will again be actuated to move the switch arm 17 9 thereof into engagement with contacts 156 and'163 to start the operation of the motor 85, the current entering through wire 159, passing through switch 97, and wire 166, through switch 109 and wires 175 and 172 to motor 85, and from motor 85 through wire 178, to negative main 177. After the table 24 has been moved from the turn table onto the return track, the stop switch 109 will be actuated to move the switch arm 180 to engage contacts 170 and 174 to break the circuit through the motor 85and bring the overhead pusher to-a stop.

When the operating car 57 is again moved to the left to actuate switch 99, the operating arm 185 thereof will be moved to engage contacts 182 and 184 whereupon the current will enter through wire 186, pass through switch 99, and wire 200, to contact 193 of switch 120, then through switch arm 189 and wire 201, to contact 197, through arm 190 and wire 202, to the motor 53 and then from motor 53 to the negative main 177 through wire 204. Upon completion of this circuit, the motor 53 will be driven at its high speed to again start the turn table, and this rotation will be continued until the plate 122 is caused to actuate switch 120 to move the single operating arm 189 to engage contact 194 and the double operating arm 190 to engage contacts 196 and 198. The current will then enter through wire 186, pass through switch 99 and wire 200 to the contact 194 of switch 20, then through arm 189 and wire 201 to contact 198, through arm 190, and wire 203 to the motor 53, and then from the motor to the negative main. Upon completion of this circuit, the motor 53 will be retarded so as to slow down the rotation of the turn table. Upon the operation of switch 120 by plate 123, the arm 189 will be moved to engage contact 191, and thus break the circuit through the motor to stop the operation of the turn table.

The electrical wiring for the opposite or right hand end'ot the system illustrated in Fig. 2, has been shown in Fig. 17, and since this wiring arrangement is substantially the same in all material respects as that disclosed in Fig. 16, a detailed description thereof is not thought to be necessary.

In Fig. 18 is disclosed the wiring arrangement for the table locating switches 146, 150 and 151. In this instance, the switch 146 is connected by means of a wire 206 with the positive main 207, while the .switch 146 is connected with the switch 150 by a wire 208 and the switch 150 connected with switch 151 by wire 209. Interposed in the circuit is a magnetic switch 210 including the spaced magnets 211 and 212, between which is pivoted the movable switch blade 213 operable to engage contact 214. The switch 151 is connected with magnet 212 by a wire 215 and from this magnet leads a wire 216 to negative main 217. Leading from the contact 214 of switch 210 is a wire 218 associated with the electric lamp or other indicating means 153 and connected with the negative main 217. Running from the switch blade 213 is a wire 219 connected to positive main 207 and connected to wire 219 is a wire 220 leading to magnet 211, while running from this magnet is a wire 221 connected to the negative main 217. lnterposed in wire 221 is a switch 222. In operation, the switch 222 is normally open and so long as at least one of the locating switches 146, 150, or 151 is held open in the manner above described, the circuit through the indicating means 153 will be incomplete so that such indicating means will not function. However, should the tables upon the return track not be in properly spaced relation so that all of the switches 146, 150 and 151 are closed, the electric current will enter from positive main 207, pass through wire 206, switch 146, wire 208, switch 150, wire 209, switch 151 and wire 215 to the magnet 212 and then from this magnet through wire 216 to the negative main 217. When the circuit through the magnet 212 is completed, said magnet will be energized to attract the switch blade 213 into engagement with contact 214 whereupon the electric current will pass from magnet 212 through switch blade 213 and wire 218 to the negative main 217, thus completing the circuit through the indicating means 153 and thereby causing such means to operate and notify the operator that the tables upon the return track are either too close together or too far apart. In order to break thecircuit through the indicating means 153, the switch 222 is then closed to complete a circuit through the magnet 211 and upon energization of this magnet, the switch arm 213 will be moved out of engagement with the contact 214. After the circuit through the indicating means has been broken, theswitch 222 is then again opened. 5

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the s irit of the invention or the scope of the su joined claims.

I claim:

1. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end,means for moving one of the tables from one track onto the transfer means, and separate means for simultaneously moving a second table from said transfer means onto the second track.

ice

2. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracksat one end, means for moving one of the tables from one track onto the transfer means, and means operable automatically by movement of the tables along the first track for moving one of said tables from the transfer means onto the second track. v

3. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track into the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, and means operable automatically to stop the operation of said last mentioned moving means after the table has been moved thereby from said transfer means.

4:. In a s stem of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, a motor for operating said last mentioned moving means, and a switch located in the path of travel of said last named moving means and operable thereby for bringing the same to a sto 5 In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, means operable by the movement of the tables along the first track for starting the operation of the second named moving means, and means located in the path of and actuated by said second named moving means for stopping the operation thereof.

6. In a system of the character described, a pair of substantially arallel tracks, tables movable along the trac s, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, and a common drive means for the separate table moving means.

7. In a system of the character described,

a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, and means operable automatically by movement of the tables along the second track to simultaneously place the two separate table moving means in operation.

8. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, and means disposed in the path of travel of and actuated by one of said table moving means for automatically bringing the two separate table moving means to a stop simultaneously.

9. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, means operable automatically by the movement of the tables along the second track for simultaneously placing the two separate table moving means in operation, and means disposed in the path of travel of and actuated by one of the table moving means for bringing the two separate table moving means to a stop simultaneously.

10. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, movable transfer means between the tracks at one end, means operable for moving the tables from one track onto the transfer means and from said transfer means onto the second track, and means for preventing the operation of said transfer means during the moving of the tables therefrom.

11. In a s stem of the character described, a pair of su stantially parallel tracks, tables movable along the tracks, movable transfer vmeans between the tracks at one end, means operable for moving the tables from one track onto the transfer means and fromsaid transfer means onto the second track, and means located in the path of and actuated by the tables as they leave the transfer means for preventing operation of said transfer means during the movement of the tables therefrom.

12. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, movable transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, and means actuated by the second mentioned table moving means for preventing the operation of said transfer means until said table moving means is brought to a predetermined position and stopped.

13. In a s stem of the character described, a pair of su stantially parallel tracks, tables movable along the tracks, movable transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, and means actuated by the transfer means for preventing the operation of said second mentioned table moving means until said transfer means has been brought to a predetermined position and stopped.

14. In a s stem of the character described, a pair of su stantially parallel tracks, tables movable along the tracks, transfer means between the tracks at one end, means for moving one of the tables from one track onto the transfer means, separate means for simultaneously moving a second table from said transfer means onto the second track, means for carrying the tables along the second track in spaced relation, and indicating means controlled by the movement of the tables for indicating to an operator when said tables are not spaced from one another a predetermined distance.

15. In a system'of the character described, a pair of substantially parallel tracks, tables movable along the tracks, rotatable transfer means between the tracks at one end, means for moving the tables from one track onto the transfer means, separate means for moving the tables from said transfer means onto the second track, and means operable automatically upon movement of the first mentioned table moving means for starting the rotation of said transfer means.

16. In a system of the character described, a pair of substantially arallel tracks, tables movable along the trac s,'rotatable transfer means between the tracks at one end, means for moving the table from one track onto the transfer means, separate means for moving the tables from said transfer means onto the second track, means for rotating said transfer means, and means operable automatically b the movement of the transfer means for gra ually bringing said transfer means to a stop.

17. In a system of the character described, a pair of substantially parallel tracks, tables movable along the tracks, transfer means between the tracks at opposite ends thereof, means for moving the tables from one track onto the adjacent transfer means, an overhead pusher for moving the tables from said transfer means onto the second track, a second overhead pusher for moving the tables from the opposite end of the second track onto the second transfer means, a third overhead pusher for moving the tables from the second named transfer means back onto the first talent? track, means for operating the first named overhead pusher, and separate means for operating the second .and third mentioned overhead pushers simultaneously.

Si ed at Toledo, in the county of Lucas and tate of Ohio, this 21st day of June 1929.

JOHN L. DRAKE. 

